Description
Calculate a Poisson background-count standard-deviation reference.
Biophysical scalar models require explicit signal, concentration, temperature, energy and geometric conventions. Effective concentration differs from dimensionless activity, a single displacement differs from mean-square displacement, and a fluorescence yield ratio needs absorption and refractive-index corrections. Supplied model parameters do not establish that the model applies to an experiment.
Calculate a Poisson background-count standard-deviation reference.
When to use this tool
Use Fluorophore Background Shot Noise Reference when you already have expectedBackgroundPhotons and need to calculate a Poisson background-count standard-deviation reference.
How to use the tool and how it works
- Enter expectedBackgroundPhotons. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read poissonStandardDeviation. Use the output convention below.
Require expectedBackgroundPhotons>=0; return sqrt(expectedBackgroundPhotons).1
A Poisson count has variance equal to its mean, so its standard deviation is the square root of the expected count. Other detector noise requires additional modeling.2
| Input field | Meaning and units | Accepted input |
|---|---|---|
| expectedBackgroundPhotons | Expected Background Photons | Required. Finite number; minimum 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| poissonStandardDeviation | sqrt(expectedBackgroundPhotons) under a Poisson-count assumption; no read-noise or signal-to-noise calculation. | Required. Finite number. |
{
"input": {
"expectedBackgroundPhotons": 25
},
"output": {
"poissonStandardDeviation": 5
}
}Limitations and assumptions
- This assumes a Poisson count with supplied mean. It is not a complete detector-noise, image uncertainty, read-noise, gain or signal-to-noise model.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Use the complete physical model, calibrated measurements and uncertainty analysis. Check reference states, photon-signal bases, diffusion assumptions and binding-constant conventions before interpreting local contributions as physical measurements.
References
-
Calculation and input contract: biophysics/fluorophore-background-shot-noise-reference — tool.io
-
Poisson Distribution — NIST/SEMATECH
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